xeriscaping: a water-efficient approach to landscaping

The summer of 2007 will almost certainly go down as one of the hottest and driest on record. Judging from what I can see in my own community, it will also be one of the "brownest” – literally. Lengthy drought and watering bans have resulted in crispy burnt lawns, severely stunted flowerbeds, wilted shrubs and stressed trees, not to mention distressed gardeners. This year, its not easy to be green. If long term forecasts (of the global warming variety) are any indication, its not about to get any easier.

At times like this – and in places such as the Oak Ridges Moraine where when water conservation is a burning issue – the drawbacks of water dependent gardens and landscapes becomes quite obvious.

Fortunately, there are water-efficient alternatives. Xeriscaping is one of them.

Xeriscape combines the Greek word “xeros” (meaning dry) with “landscape”. A trademark of the Colorado Waterwise
Council, it refers to a water-wise approach to landscaping. The concept was developed in the 1980’s in response to unsustainable landscape irrigation practices throughout the parched southwestern US. Xeriscaping has now gained wide acceptance even here in Ontario, where the demand for water in many fast-growing communities is exceeding supplies.

So, what exactly is a xeriscape?

First and foremost, xeriscapes are composed of hardy, drought tolerant plants adapted to local rainfall amounts without the need for supplementary watering. The beauty of drought-tolerant plants is that they generally remain vigorous even through dry periods. Many native plant species are particularly well suited to water efficient landscapes, as they have evolved in tandem with local rainfall conditions. Many non-native plants, including alpine and rock garden species, are similarly adapted.

Xeriscaping does not necessarily exclude species that demand more water. The key is to group these species together into distinct watering zones, and to adopt
efficient watering and irrigation practices that minimize waste and evaporation. Simple techniques include nighttime watering and the use of drip irrigation systems rather than sprinklers.

In a xeriscape, lawn areas are reduced to what is needed for practical or functional reasons, while the rest of the landscape might be devoted, for instance, to drought tolerant perennial and shrub ground covers (or, in some cases, ornamental stone beds). Alternatives to the common lawn are now also widely available, including wildflower, yarrow, fescue, clover and/or thyme lawn seed
mixes. These can be mown and will stay green through the summer with little or no watering beyond natural rainfall.

Xeriscaping must address the need for garden soil amendments. Sandy soils readily absorb water but drain quickly, whereas clay soils hold moisture but have a low absorption rate. The key, in either case, is to incorporate lots of organic matter in your garden soil to maximize water absorption and retention. Water retention is further enhanced through the extensive use of mulches. Mulches can also help minimize weed growth, and when properly selected, and can become an attractive landscape feature that enhances plantings.

Finally, a thorough xeriscaping plan should also target the collection and storage of rainwater for the garden, through the use of rainbarrels or cisterns to collect water off rooftops and pavements. Green roofs and porous pavements are other components of an effective water conservation landscape plan.

These are just a few tips to water-efficient gardening. Obviously, a successful xeriscape requires some planning and forethought. There are a number of useful publications now available on water-efficient landscaping, and you may want to consult with a professional to prepare a
proper design. Either way, the long term results are sure to please the eye and help conserve our precious water resources.